1. Field of the Invention
The present invention relates to a wireless communication device which communicates with a wireless card or wireless tag used for a credit card, reward card, or individual identification medium (e.g., a bankbook, employee card, or passport), and a wireless communication method applied to the wireless communication device.
2. Description of the Related Art
Recently, wireless cards have widely spread for reasons of information security and portability. Organizations such as ISO standardize the communication method so that wireless readers/writers and wireless cards available from various manufacturers can be utilized without any problem. For example, Jpn. Pat. Appln. KOKAI Publication No. 9-179954 discloses a technique for a wireless information processing apparatus which reads/writes data from/on a portable wireless card via a wireless communication medium.
However, when the transmission/reception antenna of the wireless reader/writer and the antenna of the wireless card are in tight contact with each other and have a similar shape, cross coupling between the antennas becomes strong, and their antenna characteristics influence each other. The antenna characteristic of the wireless reader/writer may greatly deviate from the communication frequency of the wireless card. Along with this, the wireless reader/writer may not normally receive a response from the wireless card. That is, the wireless reader/writer and wireless card which meet the standard of ISO or the like may not be able to communicate with each other.